What's fun is that this isn't just a possibility, its likely! Despite the following being a clearly artificial argument, the general shape of it is true.
Let's say that you can rate employees 1-10 on each of technical skill and employability/soft-skills, and that both are equally sought by the market. Given how attractive your company is to work for and what you pay, its quite often true that you can allocate around 12 total points between the two categories. 13 point candidates have better offers from Google; 11 point candidates fail your interview process.
If you only hire people that strongly pass a strong technical interview, ensuring that their technical skill is at least an 8/10, then your employees will have at most 4/10 soft skills.